Fanged Frog of Borneo Shows Speciation is Messy (Jake Currie, March 5, 2026, nautilus)
[D]istinctions between populations aren’t always clear-cut, and drawing the boundary can be a fraught endeavor. Take the fanged frogs of Borneo for example. One species (Limnonectes kuhlii), identified almost 200 years ago, has more recently been sliced and diced by a series of genetic analyses into as many as 18 distinct species.
But do these genetic distinctions really reflect biological reality?
To investigate, a team led by Chan Kin Onn of the University of Michigan collected DNA from fanged frogs throughout the Bornean rainforests, analyzing more than 13,000 locations in their genomes. Their findings, published in Systematic Biology, determined that the frogs do indeed belong to multiple species, but they’re clustered in six or seven distinct groups—that is, not 18.
“It’s not just one species. But it’s not 18 species, either,” Chan said in a statement.
The discrepancy exists because earlier genetic analyses focused on finding divergence between the populations using models that assumed no gene flow was taking place, meaning there was no interbreeding between the populations. But as Chan put it, “We found a ton of gene flow going on.”
It’s however many they choose to pretend.